Help! I had a kickboxing lesson the other day and couldn't get the punches and kicks right, any tips?

It was my first lesson but everyone else just seemed a lot better than me. I was told to sort of twist my hips when I kick and snap my leg forward but everytime I tried it just did not work but everyone else did great. And when I punched I kept extending my arms and I couldn't jab properly, I kept leaning forward. Am I always going to be useless?